This first line is after Samantha finds out that Deana's responce to selling her soul to bring Sammy back to life was that 'it was her job to look after her little sister' 

SAMANTHA

You've saved my life over and over. I mean, you sacrifice everything for me. Don't you think I'd do the same for you? You're my big sister. There's nothing I wouldn't do for you. And I don't care what it takes, I'm gonna get you out of this. Guess I gotta save your ass for a change.

She later begins drinking demon blood, finding it gives her special strength in hopes of defeating the demon Lilith. However, it has horrible side effects.

SAMANTHA

I've got demon blood in me, Dea! This disease pumping through my veins and I can't even rip it out or scrape it clean. I'm a whole level of freak!!

This is when Samantha confronts Deanna about her attitude about going to hell. You can either ignore Deanna's lines or read them. Either works! 

SAMANTHA

Dude. Drop the attitude, Deanna. Quit turning everything into a punchline. And you know something else? Stop trying to act like you're not afraid.

DEANNA

I'm not.

SAMANTHA

You're lying. And you may as well drop it, 'cause I can see right through you.

DEANA

 You have no idea what you're talking about.

SAMANTHA

Yeah, I do. You're scared, Deana. You're scared because you're year is running out, and you're still going to Hell, and you're freaked.

DEANNA
And how do you know that?

SAMANTHA

Because I know you!

DEANNA

Really?

DEANNA

 Yeah, because I've been following you around my entire life. I mean, I've been looking up to you since I was four, Dea. Studying you, trying to be just like my big sister. So, yeah, I know you. Better than anyone else in the entire world. And this is exactly how you act when you're terrified. And, I mean, I can't blame you. It's just...

DEANNA

What?

SAMANTHA

It's just, I wish you would drop the show and be my sister again, 'cause... just 'cause.